Baghdad, Iraq – The story was horrific, even when compared with the daily dose of brutality that Iraqis endure: 18 boys killed by a massive bomb while kicking a ball around a soccer field in one of Iraq’s most volatile cities.

State-run Iraqiya TV first reported the incident Tuesday shortly after 8 p.m., scrolling the words across the bottom of the screen. Other television stations quickly followed with their own reports.

Before the night was out, Prime Minister Nouri al-Maliki had condemned the act, as had the United Nations Children’s Fund, UNICEF.

On Wednesday, though, the U.S. military said the report was false and suggested someone had lied to stir up trouble in the western city of Ramadi, a center of Sunni insurgent activity where the crime was said to have occurred. In reality, it said, U.S. troops set off a controlled detonation of a weapons cache that went awry and injured 31 people, none seriously.

“There was no (bomb) blast, and there were no 18 children killed,” Navy Rear Adm. Mark Fox, a U.S. military spokesman, told a news briefing.

Iraqi television dropped the report Wednesday night, and some officials in Ramadi backed off their early statements, saying people may have been mixing up the purported incident with another bombing.

The one clear thing to emerge from the still-murky reports was just how easy it is to inflame already searing Sunni-Shiite tensions in Iraq, where al-Maliki’s Shiite-led government is struggling to contain sectarian bloodshed, and how difficult it is to get to the truth.

Al-Maliki’s hasty response blamed “criminal gangs,” a clear euphemism for Sunni insurgents who in recent days have attacked a college campus, restaurants and marketplaces.

“This horrendous act is affirming that these gangs are not related to Islam and Muhammad teachings, and reveal the ugly face of the princes of slaughter,” he said.

Because the initial reports came out at night, close to curfew and in a city far too dangerous for most people to be on the streets after dark, the television reports did not include footage from the scene.

Given the extent of the carnage in Iraq, the reported attack, while startling for its apparent targeting of children at play, was entirely plausible. Children and youth frequently are caught in the middle of Iraq’s sectarian war and have been targeted in the past.

In addition, Anbar province, where Ramadi is located, has been struck by a series of apparent Sunni-on-Sunni bombings recently as al-Qaeda extremists vie for dominance over the region. Earlier in the week, a Sunni mosque in the province was bombed after the imam had preached against al-Qaeda.

Bolstering the report were comments from Ramadi police and hospital officials, as well as witnesses. Many gave conflicting accounts, but that is not unusual in Iraq, where initial reports of bombings often prove to be far different from fact. Some said all the victims were young boys. Others said the victims included women. Al-Maliki’s statement said both women and children had died.

Some said the attack occurred at 3 p.m. Others said it was after 5 p.m.

One police supervisor said the bomb was so powerful that it virtually vaporized many of the victims, his explanation for the lack of bodies.

Many witnesses described seeing victims being carried away by U.S. troops who were in the area.